Radiographic image quality after interruption of the fixing stage to view the image with a viewbox

Abstract

Purpose: To evaluate the quality of radiographic images with regard to the time during which the fixing stage was interrupted to allow a preliminary reading of the image in the viewbox. Methods: Radiographs were taken with 130 Insight ® periapical films, including a step-wedge and lead plate. The films were distributed into 13 groups according to the time taken for reading in a viewbox: 0 (control), 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140 and 150 s. During processing using the temperature-time method, the films in the experimental groups were removed 5 s after immersion in the fixer, placed against the light of a viewbox for the studied times and then re-immersed in the fixer to complete the fixation process. Base-plus-fog density and the densities of the first and last degree of the step-wedge were measured immediately and after six months to calculate the contrast. Results: There were no significant differences with regard to the base-plus-fog density or the contrast values of the experimental groups when compared with the control group. Conclusion: It was concluded that interrupting the radiograph fixation process to read the image in a viewbox does not interfere with the base-plus-fog density or with the radiographic contrast, even six months after they were taken. Resumo Objetivo: Avaliar a qualidade da imagem radiográfica quanto ao tempo de leitura em negatoscópio com interrupção da etapa fixação. Metodologia: Foram radiografados 130 filmes periapicais Insight ® com um penetrômetro e placa de chumbo. Os filmes foram distribuídos em 13 grupos de acordo com o tempo de leitura em negatoscópio: 0 (controle), 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140 e 150 s. Durante o processamento pelo método temperatura-tempo, nos grupos experimentais, após 5 s de imersão no fixador, os filmes foram removidos, postos contra a luz de um negatoscópio durante os tempos estudados e imersos no fixador para completar o processo de fixação. Foram mensuradas, imediatamente e após seis meses, as densidades base e velamento e as densidades do primeiro e último degrau do penetrômetro para o cálculo do contraste.